Field of the Invention
[0001] This invention relates generally to woven fabrics, and relates more specifically
to woven fabrics for papermakers.
Background of the Invention
[0002] In the conventional fourdrinier papermaking process, a water slurry, or suspension,
of cellulosic fibers (known as the paper "stock") is fed onto the top of the upper
run of an endless belt of woven wire and/or synthetic material that travels between
two or more rollers. The belt, often referred to as a "forming fabric", provides a
papermaking surface on the upper surface of its upper run which operates as a filter
to separate the cellulosic fibers of the paper stock from the aqueous medium, thereby
forming a wet paper web. The aqueous medium drains through mesh openings of the forming
fabric, known as drainage holes, by gravity alone or with assistance from one or more
suction boxes located on the lower surface (
i.e., the "machine side") of the upper run of the fabric.
[0003] After leaving the forming section, the paper web is transferred to a press section
of the paper machine, in which it is passed through the nips of one or more pairs
of pressure rollers covered with another fabric, typically referred to as a "press
felt." Pressure from the rollers removes additional moisture from the web; the moisture
removal is often enhanced by the presence of a "batt" layer on the press felt. The
paper is then conveyed to a drier section for further moisture removal. After drying,
the paper is ready for secondary processing and packaging.
[0004] Typically, papermaker's' fabrics are manufactured as endless belts by one of two
basic weaving techniques. In the first of these techniques, fabrics are flat woven
by a flat weaving process, with their ends being joined to form an endless belt by
any one of a number of well-known joining methods, such as dismantling and reweaving
the ends together (commonly known as splicing), or sewing a pin-seamable flap on each
end or a special foldback, then reweaving these into pin-seamable loops. In a flat
woven papermaker's' fabric, the warp yarns extend in the machine direction and the
filling yarns extend in the cross machine direction. In the second technique, fabrics
are woven directly in the form of a continuous belt with an endless weaving process.
In the endless weaving process, the warp yarns extend in the cross machine direction
and the filling yarns extend in the machine direction. As used herein, the terms "machine
direction" (MD) and "cross machine direction" (CMD) refer, respectively, to a direction
aligned with the direction of travel of the papermaker's' fabric on the papermaking
machine, and a direction parallel to the fabric surface and traverse to the direction
of travel. Both weaving methods described hereinabove are well known in the art, and
the term "endless belt" as used herein refers to belts made by either method.
[0005] When tissue paper is being formed, typically a forming fabric with a top surface
having a relatively fine mesh is employed. Such a fabric can reduce the tendency of
the paper to have "pin holes." Also, because tissue paper is typically formed on paper
machines that run at high speeds with high permeability fabrics, tissue forming fabrics
generally are relatively thin (
i.e., of low caliper); low caliper fabrics tend to drain quickly (due to a lesser void
volume) and are therefore often more effective than thicker fabrics. In addition,
the high operating rate of a tissue forming machine can also cause the "sheet release"
properties of a tissue forming fabric to be very important. In contrast to forming
fabrics for higher grades of paper, such as printer paper, the "coplanarity" of the
papermaking surface is generally less critical for tissue forming fabrics, as a fabric
having less coplanar surface can produce a softer paper (which is, of course, an important
quality in tissue). Further, a typical tissue forming fabric is "CMD-predominant"
on its top surface;
i.e., the CMD yarns of the top surface tend to comprise more of the top surface than do
the MD yarns and provide much of the fiber support for the paper stock fibers.
[0006] The foregoing demonstrates that forming fabrics for tissue paper can have much different
performance characteristics than those for forming newsprint, printer paper, and other
finer paper grades. As such, forming fabrics suitable for fine paper grades, such
as those illustrated in U.S. Patent Nos. 4,987,929; 5,518,042; and 5,937,914 to Wilson,
may not be suitable for the formation of tissue paper. Fabrics that are designed for
tissue paper formation, such as those illustrated in U.S. Patent Nos. 5,025,839 to
Wright and 5,857,498 to Barreto, can have insufficient permeability under certain
circumstances. One other proposed tissue forming fabric, that illustrated in U.S.
Patent No. 5,421,374 to Wright, addresses the permeability issue by including only
one bottom CMD yarn for every three top CMD yarns, but this fabric can have problems
with the top CMD yarns bunching together such that there is not uniform spacing between
the top CMD yarns. U.S. Patent No. 4,421,189 to Baker describes a papermaker's fabric
having a conventional 1x2 twill pattern.
Summary of the Invention
[0007] In view of the foregoing, it is an object of the present invention to provide a papermaker's
fabric suitable for forming tissue paper.
[0008] It is another object of the present invention to provide a tissue forming fabric
that addresses the permeability and top CMD spacing uniformity problems described
above.
[0009] These and other objects are satisfied by the present invention, which includes a
papermaker's fabric that can provide suitable permeability, surface structure, and
top CMD yarn spacing for tissue formation. The papermaker's fabric comprises: a base
fabric structure including machine direction yarns and primary cross machine direction
yarns interlacing to form a papermaking surface, wherein the machine direction yarns
and primary cross machine direction yarns are interlaced in a pattern having a harness
repeat of greater than two. The fabric also includes first and second companion cross
machine direction yarns positioned between each pair of adjacent primary cross machine
direction yarns. Each first companion cross machine direction yarn has an interlacing
pattern relative to the machine direction yarns that is identical to a first of the
pair of adjacent primary cross machine direction yarns, and each second companion
cross machine direction yarn has an interlacing pattern relative to the machine direction
yarns that is identical to a second of the pair of adjacent primary cross machine
direction yarns. The first companion cross machine direction yarn is positioned between
the second primary and companion cross machine direction yarns. The primary cross
machine direction yarns have a first diameter, and the first and second companion
yarns have a second diameter, wherein the ratio between the first and second diameters
is between about 0.9 and 1.1. In this configuration, the companion paper side cross
machine direction yarns tend to remain separated from each other, thereby providing
a surface structure and a permeability that can suitably produce tissue paper.
[0010] In another embodiment, a papermaker's fabric of the present invention comprises machine
direction yarns interwoven with first and second sets of top cross machine direction
yarns and a bottom set of cross machine direction yarns in a repeat unit. The first
and second sets of top cross machine direction yarns are arranged in alternating fashion
such that one of the first set of cross machine direction yarns resides between two
of the second set of top cross machine direction yarns, and one of the second set
of top cross machine direction yarns resides between two of the first set of top cross
machine direction yarns. Each of the machine direction yarns of the repeat unit passes
below at least one of the bottom machine direction yarns, and each of the machine
direction yarns passes either (a) above two adjacent top cross machine direction yarns
of the first set and below one of the top cross machine direction yarns of the second
set positioned therebetween, or (b) above two adjacent top cross machine direction
yarns of the second set and below one of the top cross machine direction yarns of
the first set positioned therebetween. This configuration can also provide a surface
structure and permeability suitable for forming tissue paper. It is preferred that,
in this configuration, the paper side cross machine direction yarns comprising the
first set be formed of a material that has a different elastic modulus (
i.e., differs in flexibility) than the material from which the paper side cross machine
direction yarns are formed.
Brief Description of the Figures
[0011]
Figure 1 is a top view of the papermaking surface of a double layer forming fabric of the
present invention.
Figure 2 is a top view of the bottom layer of the double layer forming fabric of Figure 1.
Figures 3A and 3B are section views taken along lines 3A-3A and 3B-3B of Figure 1, respectively, showing the interrelationship between two typical MD yarns, primary
CMD yarns, companion CMD yarns, and machine side CMD yarns.
Figure 4 is an enlarged partial perspective view of the fabric of Figure 1 showing the interrelationship of companion CMD yarns to one another and to their
adjacent primary CMD yarns.
Figure 5 is a top view of the papermaking surface of an alternative double layer forming fabric
embodiment of the present invention.
Figure 6 is a top view of the bottom layer of the double layer forming fabric of Figure 5.
Figures 7A and 7B are section views taken along lines 7A-7A and 7B-7B of Figure 5, respectively, showing the interrelationship between typical MD yarns, primary CMD
yarns, companion CMD yarns, and machine side CMD yarns.
Figure 8 is an enlarged partial perspective view of the fabric of Figure 5 showing the interrelationship of companion CMD yarns to one another and to their
adjacent primary CMD yarns.
Detailed Description of the Invention
[0012] The present invention will now be described more particularly hereinafter with reference
to the accompanying drawings, in which present embodiments of the invention are shown.
The invention, however, be embodied in many different forms and is not limited to
the embodiments set forth herein; rather, these embodiments are provided so that the
disclosure will fully convey the scope of the invention to those skilled in the art.
Like numbers refer to like components throughout. The dimensions and thicknesses for
some components and layers may be exaggerated for clarity.
[0013] The present invention is directed to papermaker's' woven fabrics. For ease of understanding
of the concepts of the invention, the first fabric illustrated herein will be described
as if a base fabric layer were initially woven and then additional yarns added. The
hypothetical base fabric layer includes MD yarns and CMD yarns referred to as "primary"
CMD yarns. The additional yarns are referred to as "companion" CMD yarns. Of course,
this fabric embodiment will typically be woven in a one-step weaving process, with
the primary CMD yarns and the companion CMD yarns being woven in sequence.
[0014] Turning now to the Figures, a double layer fabric, designated broadly at
50, is illustrated in
Figures 1 through
4. In the illustration in
Figure 1 that encompasses a repeat unit, the fabric
50 includes MD yarns
52, 54, 56, 58, 60, 62, 64, and
66. Eight primary CMD yarns
70, 72, 74, 76, 78, 80, 82, and
84 are interwoven with the MD yarns in a twill pattern such that each CMD yarn passes
over seven MD yarns, passes beneath an MD yarn, then repeats this pattern;
i.e., the "floats" of the primary CMD yarns
70 through
84 (those portions of the primary CMD yarns which extend over multiple adjacent MD yarns)
form a "twill" pattern which extends across the fabric
50 at an angle at approximately 45° to the MD yarns. The eight harness fabric
50 is constructed so that the MD knuckles (locations where an MD yarn passes over a
single primary CMD yarn) of adjacent MD yarns are offset in the cross machine direction
by three primary CMD yarns; for example, MD yarn
52 passes over primary CMD yarn
70, and MD yarn
54 passes over primary CMD yarn
76.
[0015] Figure 2 illustrates the machine side layer of the fabric
50. Machine side CMD yarns
90, 92, 94, 96, 98, 100, 102, and
104 are positioned below the primary CMD yarns
70 through
84 described above, with each machine side CMD yarn preferably being positioned substantially
directly beneath a respective paper side primary CMD yarn. In
Figures 3A and
3B, typical MD yarns
52,
54 are shown passing from the paper side of the fabric
50 to interweave the machine side CMD yarns. Specifically, in this instance, the MD
yarn
52 passes over the machine side CMD yarns
90,
92 and
94, under machine side CMD yarn
96, over machine side CMD yarn
98, under machine side CMD yarn
100, and above machine side CMD yarns
102 and
104 (
Figure 3A). Adjacent MD yarn
54 passes below machine side CMD yarn
90, above machine side CMD yarns
92-100, below machine side CMD yarn
102, and above machine side CMD yarn
104. (
Figure 3B).
[0016] Referring again to
Figures 1 and
2, a pair of companion CMD yarns is positioned between each pair of primary CMD yarns.
Each companion CMD yarn has the identical weave pattern to a primary CMD yarn separated
from it by only one other companion CMD yarn. For clarity, the numerical designation
of each companion CMD yarn matches that of the primary CMD yarn with its identical
weave pattern, with an "
a" or "
b" designation added to indicate a companion CMD yarn. Thus, the companion CMD yarn
70b has the identical weave pattern to primary CMD yarn
70, companion CMD yarns
72a, 72b have the identical weave pattern of primary CMD yarn
72, and companion CMD yarns
74a, 74b have the identical weave pattern to primary CMD yarn
74. The same is true for companion CMD yarns
76a, 76b, 78a, 78b, 80a, 80b, 82a, 82b, 84a, and
84b, each of which has the identical weave pattern as the primary CMD yarn with its corresponding
designating number (companion CMD yarn
84b is located adjacent primary CMD yarn
70 is this repeat unit). In each instance, the companion CMD yarn is separated from
its corresponding primary CMD yarn by one other companion CMD yarn, which, of course,
is also separated from its corresponding primary CMD yarn by the first companion CMD
yarn.
[0017] In this configuration, the MD yarns follow an "over 1/under 1/over 1/under 1/over
1" sequence as they interweave with two companion CMD yarns, a primary CMD yarn, and
two more companion CMD yarns. For example, MD yarn
58 passes over companion yarn
72a, below companion yarn
70b, above primary CMD yarn
72, below companion yarn
74a, and above companion yarn
72b. This sequence can encourage the primary and companion CMD yarns to remain relatively
uniformly separated from one another, particularly when the companion CMD yarns are
of a similar diameter as the primary CMD yarns and/or are formed of a stiffer material
than the primary CMD yarns, as is described in greater detail below.
[0018] Preferably, the companion CMD yarns are of a similar, or even essentially identical,
diameter as the primary CMD yarns in the fabric 50. The selected sizes of the companion,
primary and machine side CMD yarns and the MD yarns are typically governed by the
performance requirements of the fabric. Generally, the ratio of the diameters of the
companion CMD yarns and the primary CMD yarns should be between about 0.9 and 1.1,
with ratio of between about 0.95 and 1.05 being preferred and a ratio of about 1.0
being more preferred. Suitable yarn diameters for the primary, companion and machine
side CMD yarns and the MD yarns are shown in the following table:
Primary CMD yarns |
Companion CMD yarns |
Machine Side CMD Yarns |
MD Yarns |
Papermaking Application |
Number/ Inch |
Dia. (mm) |
Dia. (mm) |
Dia. (mm) |
Dia. (mm) |
|
27 |
.15 |
.15 |
.30 |
.17 |
fine/news |
27 |
.20 |
.20 |
.36 |
.22 |
brown |
30 |
.11 |
.11 |
.25 |
.12 |
tissue |
30 |
.13 |
.13 |
.25 |
.12 |
fine/tissue |
30 |
.13 |
.13 |
.28 |
.15 |
fine/tissue |
33 |
.11 |
.11 |
.22 |
.12 |
tissue |
33 |
.11 |
.11 |
.25 |
.15 |
tissue |
[0019] The form of the yarns utilized in the fabrics of the present invention can vary,
depending upon the desired properties of the final papermaker's' fabric. For example,
the yarns may be multifilament yarns, monofilament yarns, twisted multifilament or
monofilament yarns, spun yarns, or any combination thereof. Also, the materials comprising
yarns employed in the fabric of the present invention may be those commonly used in
papermaker's' fabric. For example, the yarns may be formed of cotton, wool, polypropylene,
polyester, aramid, nylon, or the like. The skilled artisan should select a yarn material
according to the particular application of the final fabric. In particular, round
monofilament yarns formed of polyester or nylon are preferred.
[0020] The primary CMD yarns may be formed of the same material as the companion CMD yarns
or be formed of a different material (and preferably a more flexible material) than
the companion CMD yarns. For example, the primary CMD yarns may be formed of a medium
modulus polyester having a relative elongation of 10 to 20 percent at 3 g per 1,11
dtex (denier), and the companion CMD yarns may be formed of a medium to high modulus
polyester having a relative elongation of 3 to 20 percent at 3 g per 1,11 dtex (denier).
In this configuration, the MD yarns are more likely to "crimp" as they cross the companion
CMD yarns (see
Figure 4). This crimping in the MD yarns as they form single float knuckles (encouraged by
the "over 1/under 1/over 1/under 1/over 1" configuration of the MD yarns on the top
surface) tends to maintain the companion CMD yarns in their original "as woven" positions
within the papermaking surface (rather than pairs of adjacent companion yarns being
forced toward each other by uncrimped MD yarns -
see U.S. Patent No. 5,937,914 to Wilson for an explanation of this effect). In their
original (and maintained) positions, the companion CMD yarns are relatively uniformly
separated from each other, which provides a desirable papermaking surface for forming
tissue paper.
[0021] The MD yarn crimping can be further encouraged by weaving the MD yarns at a lower
tension than is typical. For example, the weaving tension of MD yarns having a diameter
of 0.15 mm may be lowered to a level of between about 60 and 120 g per yarn.
[0022] In this configuration, the fabric
50 has three paper side CMD yarns for every machine side CMD yarn. As a result, the
fabric should have good permeability compared to fabrics with a lower ratio of paper
side CMD yarns to machine side CMD yarns. However, the fabric
50 can address the absence of paper side CMD yarn uniformity often found in other fabrics
with this 3:1 ratio. It should also be noted that the fabric
50 is also configured such that all of the floats of each primary and companion CMD
yarn contribute to the twill line. This twill density can reduce the visual effect
of fabric marking on paper produced with the fabric. This concept can be extended
to virtually any double layer base fabric, including seven harness double layer fabrics,
the structures of which are well-known to those skilled in this art and need not be
described in detail herein.
[0023] Those skilled in this art will appreciate that this concept of companion yarns can
be applied to virtually any fabric, including plain weaves, twills, satins, and the
like. It can be employed as the paper side of single, double and triple layer fabrics,
whether interlaced by common MD yarns (such as the fabric
50) or formed as separate fabric layers of a laminated fabric, such as those described
in U.S. Patent No. 5,277,967 to Zehle. It is preferred that the fabrics of the present
invention have a harness repeat of greater than 2 (
i.e., for fabrics other than 1x1 plain weave fabrics).
[0024] The positive impact of the "over 1/under 1/over 1" configuration on crimping of MD
yarns and, consequently, maintenance of separation of paper side CMD yarns may also
be seen in an alternative fabric embodiment, designated broadly at
200 in
Figures 5 through
8. The fabric
200 comprises eight MD yarns
202, 204, 206, 208, 210, 212, 214, 216 interwoven with sixteen paper side CMD yarns
220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250 and eight machine side CMD yarns
260, 262, 264, 266, 268, 270, 272, 274. The paper side CMD yarns can be subdivided into two sets of alternating yarns: one
set being paper side CMD yarns
220, 224, 228, 232, 236, 240, 244 and
248, and the second set of paper side CMD yarns being
222, 226, 230, 234, 238, 242, 246 and
250.
[0025] As can be seen in
Figure 5, each MD yarn passes above one paper side CMD yarn, below the immediately adjacent
paper side CMD, above the next adjacent paper side CMD yarn, and below the remaining
CMD paper side yarns. For example, the MD yarn
202 passes over paper side CMD yarn
220, below paper side CMD yarn
222, over paper side CMD yarn
224, and below the remaining paper side CMD yarns. The remaining MD yarns also have this
"over 1/under 1/over 1" pattern with paper side CMD yarns.
[0026] Notably, each MD yarn passes over two paper side yarns that are either both in the
first set or both in the second set of paper side CMD yarns, and each MD yarn passes
under a paper side CMD yarn that is not in the set of paper side yarns that the MD
yarns passes over. Again using MD yarn
202 as an example, it passes over paper side CMD yarns
220 and
224, each of which are in the first set of paper side CMD yarns as defined above, and
below paper side CMD yarn
222, which is in the second set of paper side CMD yarns.
[0027] Adjacent MD yarns are offset from each other in the machine direction by either five
or seven paper side CMD yarns. For example, MD yarn
202 first passes over paper side CMD yarn
220, while adjacent MD yarn
204 first passes over paper side yarn
230, which is five yarns away from paper side CMD yarn
220 in the machine direction. MD yarn
206 first passes over paper side CMD yarn
244, which is seven paper side CMD yarns away from the paper side CMD yarn
230 first passed over by adjacent MD yarn
204. This alternating offset of five paper side CMD yarns, then seven paper side CMD yarns,
for adjacent MD yarns continues throughout the repeat unit.
[0028] As a result of this weave pattern, the "companion" yarn concept of the fabric
50 described above is extended to the fabric
200 also. Each paper side CMD yarn has the identical weave pattern to another paper side
CMD yarn separated from it by one paper side CMD yarn. For example, paper side CMD
yarns
220 and
224 both pass under MD yarns
202 and
208 and over the other MD yarns. This pattern forms the "over1/under1/over1" pattern
described above that can encourage desirable crimping in the MD yarns.
[0029] Referring now to
Figure 6, the machine side of the fabric is formed by the interweaving of the MD and machine
side CMD yarns. One machine side CMD yarn is positioned generally beneath a respective
paper side CMD yarn. Each MD yarn passes below two machine side CMD yarns separated
by one machine side CMD yarn. For example, MD yarn
202 passes below machine side CMD yarns
266 and
270 (passing over machine side CMD yarn
268 that is positioned between machine side yarns
268,
272). Similarly, MD yarn
204 passes below machine side CMD yarns
272 and
260 and above machine side CMD yarn
272 (yarn
260 would be the next machine side CMD yarn in the repeat unit). Notably, half of the
MD yarns (exemplified by MD yarn
202 in
Figure 7A), after passing above a paper side CMD yarn, pass above one machine side CMD yarn
before passing below a machine side CMD yarn, while the other half of the MD yarns
(exemplified by MD yarn
204 in
Figure 7B), pass above two machine side CMD yarns after passing over a paper side CMD yarn before
passing below a machine side CMD yarn.
[0030] The sizes, materials and configurations of the yarns for the fabric
200 can take the form described hereinabove for the fabric
50. An exemplary fabric is formed of MD yarns having a diameter of 0.15 mm, paper side
CMD yarns having a diameter of 0.11 mm, and machine side CMD yarns having a diameter
of 0.25 mm. Like the fabric
50 described above, it may be desirable to reduce the typical weaving tension for the
MD yarns. Also as with the fabric
50, it may be desirable to form some of the paper side CMD yarns of a more flexible material.
[0031] In this configuration, the fabric
200 can provide a desirable combination of permeability and fiber support for tissue
forming fabrics. The top surface of the fabric
200 includes the "over 1/under 1/over 1" MD yarn weaving pattern that can encourage MD
yarn crimping and, as a result, uniform separation of paper side CMD yarns. Accordingly,
the fabric can furnish a suitable surface for forming tissue paper.
[0032] It should also be understood that, although fabrics for forming tissue have been
discussed herein, this concept can be extended to fabrics for forming other types
of paper. For example, similar weave patterns can be used to form brown paper by increasing
yarn size, including one embodiment following the weave pattern illustrated in
Figures 1 through
4 in which paper side CMD yarns having a diameter of 0.23mm, machine side CMD yarns
having a diameter of 0.40mm, and machine direction yarns having a diameter of 0.27mm
are employed. Those skilled in this art will recognize other extensions of this concept
can apply to other types of paper.
[0033] The foregoing embodiments are illustrative of the present invention, and are not
to be construed as limiting thereof. The invention is defined by the following claims.
1. A papermaker's fabric (50), comprising:
a base fabric structure including machine direction yarns (52, 54, 56, 58, 60, 62,
64, 66) and primary cross machine direction yarns (70, 72, 74, 76, 78, 80, 82, 84)
interlacing to form a papermaking surface, said machine direction yarns and primary
cross machine direction yarns being interlaced in a pattern having a harness repeat
of greater than two;
first and second companion cross machine direction yarns positioned between each pair
of adjacent primary cross machine direction yarns (70, 72; 72, 74; 74, 76; ...)
wherein each first companion cross machine direction yarn (70b, 72b, 74b,...)
has an interlacing pattern relative to said machine direction yarns that is identical
to a first (70, 72, 74, ...) of said pair of adjacent primary cross machine direction
yarns (70, 72; 72, 74; 74, 76; ...) and wherein each second companion cross machine
direction yarn (72a, 74a, 76a, ...) has an interlacing pattern relative to said machine
direction yarns that is identical to a second (72, 74, 76, ...) of said pair of adjacent
primary cross machine direction yarns (70, 72; 72, 74; 74, 76; ...), and wherein said
first companion cross machine direction yarn (70b, 72b, 74b, ...) is positioned between
said second primary (72, 74, 76, ...) and companion (72a, 74a, 76a,...) cross machine
direction yarns; and
wherein said primary cross machine direction yarns (70, 72, 74, ...) have a first
diameter, and said first and second companion yarns (70b, 72a, 72b, 74a, 74b, 76a,
...) have a second diameter, and the ratio between said first and second diameters
is between about 0.9 and 1.1.
2. The papermaker's fabric defined in Claim 1, wherein said second companion cross machine
direction yarn (72a, 74a, 76a, ...) is positioned between said first primary (70,
72, 74, ...) and companion (70b, 72b, 74b, ...) cross machine direction yarns.
3. The papermaker's fabric defined in Claim 1, wherein said repeating harness pattern
is a twill pattern.
4. The papermaker's fabric defined in Claim 3, wherein said twill pattern is a 2 x 1
twill pattern.
5. The papermaker's fabric defined in Claim 1, wherein said ratio between said first
and second diameters is between 0.95 and 1.05.
6. The papermaker's fabric defined in Claim 1, wherein said ratio between said first
and second diameters is about 1.0.
7. The papermaker's fabric defined in Claim 1, wherein said primary cross machine direction
yarns (70, 72, 74, 76, 78, 80, 82, 84) are formed of a first material, and said companion
cross machine direction yarns (70b, 72a, 72b, 74a, 74b, 76a, ...) are formed of a
second material that differs from said first material.
8. The papermaker's fabric defined in Claim 7, wherein said second material has a higher
stiffness than said first material.
9. The papermaker's fabric defined in Claim 1, further comprising additional cross machine
direction yarns interlaced with said machine direction yarns to form a machine side
surface.
10. A method of making paper, comprising the steps of:
providing a papermaker's fabric, said papermaker's fabric comprising:
a base fabric structure including machine direction yarns and primary cross machine
direction yarns interlacing to form a papermaking surface, said machine direction
yarns and primary cross machine direction yarns being interlaced in a pattern having
a harness repeat of greater than 2;
two companion cross machine direction yarns positioned between each pair of adjacent
primary cross machine direction yarns;
wherein each first companion cross machine direction yarn has an interlacing pattern
relative to said machine direction yarns that is identical to a first of said pair
of adjacent primary cross machine direction yarns, and wherein each second companion
cross machine direction yarn has an interlacing pattern relative to said machine direction
yarns that is identical to a second of said pair of adjacent primary cross machine
direction yarns, and
wherein said first companion cross machine direction yarn is positioned between said
second primary and companion cross machine direction yarns; and
wherein said primary cross machine direction yarns have a first diameter, and said
first and second companion yarns have a second diameter, and the ratio between said
first and second diameters is between about 0.9 and 1.1;
applying paper stock to said papermaker's fabric; and
removing moisture from said paper stock.
1. Papiermaschinensieb (50), das folgendes aufweist:
eine textile Flächengebilde-Grundstruktur, die Machinenrichtungsfäden (52, 54, 56,
58, 60, 62, 64, 66) und primäre Maschinenquerrichtungsfäden (70, 72, 74, 76, 78, 80,
82, 84) aufweist, die miteinander verwoben sind, um eine Papiererzeugungsoberfläche
zu bilden, wobei die Maschinenrichtungsfäden und die primären Maschinenquerrichtungsfäden
in einem Muster miteinander verwoben sind, das einen Harnischrapport von mehr als
zwei hat.
erste und zweite begleitende Maschinenquerrichtungsfäden, die zwischen jedem Paar
von benachbarten primären Maschinenquerrichtungsfäden (70, 72; 72, 74; 74, 76; ...)
positioniert sind;
wobei jeder erste begleitende Maschinenquerrichtungsfaden (70b, 72b, 74b, ...)
ein Bindungsmuster relativ zu den Maschinenrichtungsfäden hat, das mit einem ersten
(70, 72, 74, ...) von dem Paar von benachbarten primären Maschinenquerrichtungsfäden
(70, 72; 72, 74; 74, 76; ...) identisch ist, und wobei jeder zweite begleitende Maschinenquerrichtungsfaden
(72a, 74a, 76a, ...) ein Bindungsmuster relativ zu den Maschinenrichtungsfäden hat,
das mit einem zweiten (72, 74, 76, ...) von dem Paar von benachbarten primären Maschinenquerrichtungsfäden
(70, 72; 72, 74; 74, 76; ...) identisch ist, und wobei der erste begleitende Maschinenquerrichtungsfaden
(70b, 72b, 74b, ...) zwischen den zweiten primären (72, 74, 76, ...) und begleitenden
(72a, 74a, 76a, ...) Maschinenquerrichtungsfäden positioniert ist; und
wobei die primären Maschinenquerrichtungsfäden (70, 72, 74, ...) einen ersten Durchmesser
haben und die ersten und zweiten begleitenden Fäden (70b, 72a, 72b, 74a, 74b, 76a,
...) einen zweiten Durchmesser haben und das Verhältnis zwischen dem ersten und dem
zweiten Durchmesser zwischen ungefähr 0,9 und 1,1 ist.
2. Papiermaschinensieb nach Anspruch 1, wobei der zweite begleitende Maschinenquerrichtungsfaden
(72a, 74a, 76a, ...) zwischen den ersten primären (70, 72, 74, ...) und begleitenden
(70b, 72b, 74b, ...) Maschinenquerrichtungsfäden positioniert ist.
3. Papiermaschinensieb nach Anspruch 1, wobei das sich wiederholende Harnischmuster eine
Köperbindung ist.
4. Papiermaschinensieb nach Anspruch 3, wobei die Köperbindung eine 2 x 1 Köperbindung
ist.
5. Papiermaschinensieb nach Anspruch 1, wobei das Verhältnis zwischen dem ersten und
dem zweiten Durchmesser zwischen 0,95 und 1,05 ist.
6. Papiermaschinensieb nach Anspruch 1, wobei das Verhältnis zwischen dem ersten und
dem zweiten Durchmesser ungefähr 1,0 ist.
7. Papiermaschinensieb nach Anspruch 1, wobei die primären Maschinenquerrichtungsfäden
(70, 72, 74, 76, 78, 80, 82, 84) aus einem ersten Material gebildet sind, und die
begleitenden Maschinenquerrichtungsfäden (70b, 72a, 72b, 74a, 74b, 76a, ...) aus einem
zweiten Material gebildet sind, das von dem ersten Material verschieden ist.
8. Papiermaschinensieb nach Anspruch 7, wobei das zweite Material eine größere Steifigkeit
als das erste Material hat.
9. Papiermaschinensieb nach Anspruch 1, das ferner zusätzliche Maschinenquerrichtungsfäden
aufweist, die mit den Maschinenrichtungsfäden verwoben sind, um eine maschinenseitige
Oberfläche zu bilden.
10. Papierherstellungsverfahren, das die folgenden Schritte aufweist:
Bereitstellen eines Papiermaschinensiebs, das folgendes aufweist:
eine textile Flächengebilde-Grundstruktur, die Maschinenrichtungsfäden und primäre
Maschinenquerrichtungsfäden aufweist, die miteinander verwoben sind, um eine Papiererzeugungsoberfläche
zu bilden, wobei die Maschinenrichtungsfäden und die primären Maschinenquerrichtungsfäden
in einem Muster miteinander verwoben sind, das einen Harnischrapport von mehr als
zwei hat;
zwei begleitende Maschinenquerrichtungsfäden, die zwischen jedem Paar von benachbarten
primären Maschinenquerrichtungsfäden positioniert sind,
wobei jeder erste begleitende Maschinenquerrichtungsfaden ein Bindungsmuster relativ
zu den Maschinenrichtungsfäden hat, das mit einem ersten von dem Paar von benachbarten
primären Maschinenquerrichtungsfäden identisch ist, und wobei jeder zweite begleitende
Maschinenquerrichtungsfaden ein Bindungsmuster relativ zu den Maschinenrichtungsfäden
hat, das mit einem zweiten von dem Paar von benachbarten primären Maschinenquerrichtungsfäden
identisch ist, und wobei der erste begleitende Maschinenquerrichtungsfaden zwischen
den zweiten primären und begleitenden Maschinenquerrichtungsfäden positioniert ist;
und wobei die primären Maschinenquerrichtungsfäden einen ersten Durchmesser haben
und die ersten und zweiten begleitenden Fäden einen zweiten Durchmesser haben und
das Verhältnis zwischen dem ersten und dem zweiten Durchmesser zwischen ungefähr 0,9
und 1,1 ist;
Aufbringen von Papierbrei auf das Papiermaschinensieb; und
Entfernen von Feuchtigkeit aus dem Papierbrei.
1. Toile synthétique de papeterie, comprenant :
- un support textile comprenant des fils en sens machine (52, 54, 56, 58, 60, 62,
64, 66) et des fils en sens machine croisé principaux (70, 72, 74, 76, 78, 80, 82,
84) qui s'entrelacent pour former une surface de fabrication du papier, lesdits fils
en sens machine et lesdits fils en sens machine croisé principaux étant entrelacés
dans un motif présentant une répétition de harnais supérieur à deux ;
- des premiers et second fils en sens machine croisé compagnons positionnés entre
chaque paire de fils en sens machine croisé principaux (70, 72 ; 72, 74 ; 74, 76 ;
...) ;
- dans laquelle chaque premier fil en sens machine croisé compagnon (70b, 72b, 74b,
...) présente un motif d'entrelacement par rapport auxdits fils en sens machine qui
est identique à une première (70, 72, 74, ...) de ladite paire de fils en sens machine
croisé principaux adjacents (70, 72 ; 72, 74 ; 74, 76, ...), et dans laquelle chaque
deuxième fil en sens machine croisé compagnon (72a, 74a, 76a, ...) présente un motif
d'entrelacement par rapport auxdits fils en sens machine qui est identique à une deuxième
(72, 74, 76, ...) de ladite paire de fils en sens machine croisé principaux adjacents
(70, 72 ; 72, 74 ; 74, 76 ; ...) et dans laquelle ledit premier fil en sens machine
croisé compagnon (70b, 72b, 74b, ...) est positionné entre lesdits deuxièmes fils
en sens machine croisé principaux (72, 74, 76) et compagnons (72a, 74a, 76a, ...)
; et
- dans laquelle lesdits fils en sens machine croisé principaux (70, 72, 74, ...) présentent
un premier diamètre, et lesdits premiers et deuxièmes fils compagnons (70b, 72a, 72b,
74a, 74b, 76a, ...) présentent un deuxième diamètre, et le rapport entre lesdits premier
et deuxième diamètres est compris entre 0,9 et 1,1.
2. Toile synthétique de papeterie selon la revendication 1, dans laquelle ledit deuxième
fil en sens machine croisé compagnon (72a, 74a, 76a, ...) est positionné entre lesdits
fils en sens machine croisé principaux (70, 72, 74, ...) et compagnons (70b, 72b,
74b, ...).
3. Toile synthétique de papeterie selon la revendication 1, dans laquelle ledit motif
de harnais répété est un motif sergé.
4. Toile synthétique de papeterie selon la revendication 3, dans laquelle ledit motif
sergé est un motif sergé 2 x 1.
5. Toile synthétique de papeterie selon la revendication 1, dans laquelle ledit rapport
entre lesdits premier et deuxième diamètres est compris entre 0,95 et 1,05.
6. Toile synthétique de papeterie selon la revendication 1, dans laquelle ledit rapport
entre lesdits premier et deuxième diamètres est d'environ 1,0.
7. Toile synthétique de papeterie selon la revendication 1, dans laquelle lesdits fils
en sens machine croisé principaux (70, 72, 74, 76, 78, 80, 82, 84) sont formés à partir
d'un premier matériau, et lesdits fils en sens machine croisé compagnons (70b, 72a,
72b, 74a, 74b, 76a, ...) sont formés à partir d'un deuxième matériau différent dudit
premier matériau.
8. Toile synthétique de papeterie selon la revendication 7, dans laquelle ledit deuxième
matériau présente une rigidité supérieure audit premier matériau.
9. Toile synthétique de papeterie selon la revendication 1, comprenant en outre des fils
en sens machine croisé supplémentaires entrelacés avec lesdits fils en sens machine
pour former une surface côté machine.
10. Procédé de fabrication du papier comprenant les étapes consistant à :
- fournir une toile synthétique de papeterie, ladite toile synthétique de papeterie
comprenant :
- un support textile comprenant des fils en sens machine et des fils en sens machine
croisé principaux qui s'entrelacent pour former une surface de fabrication du papier,
lesdits fils en sens machine et lesdits fils en sens machine croisé principaux étant
entrelacés dans un motif présentant une répétition de harnais supérieur à 2 ;
- deux fils en sens machine croisé compagnons positionnés entre chaque paire de fils
en sens machine croisé principaux ;
- dans laquelle chaque premier fil en sens machine croisé compagnon présente un motif
d'entrelacement par rapport auxdits fils en sens machine qui est identique à une première
de ladite paire de fils en sens machine croisé principaux adjacents, et dans laquelle
chaque deuxième fil en sens machine croisé compagnon présente un motif d'entrelacement
par rapport auxdits fils en sens machine qui est identique à une deuxième de ladite
paire de fils en sens machine croisé principaux adjacents et dans laquelle ledit premier
fil en sens machine croisé compagnon est positionné entre lesdits deuxièmes fils en
sens machine croisé principaux et compagnons ; et
- dans laquelle lesdits fils en sens machine croisé principaux présentent un premier
diamètre, et lesdits premiers et deuxièmes fils compagnons présentent un deuxième
diamètre, et le rapport entre lesdits premier et deuxième diamètres est compris entre
0,9 et 1,1 ;
- appliquer de la pâte à papier sur ladite toile synthétique de papeterie ; et
- enlever l'humidité de ladite pâte à papier.